Year	% of revenue
1990	9.824982889388627
1991	10.710182250396198
1992	7.507383428066368
1993	9.615470776675105
1994	8.51916216957834
1995	7.769608452626664
1996	7.386462894400207
1997	8.735441140656345
1998	8.489994820504965
1999	10.917613178669244
2000	8.70591388642777
2001	9.477656491003438
2002	10.59070771327956
2003	11.05023193469962
2004	5.394899684014649
2005	4.005943420203717
2006	5.9947945901265465
2007	4.368297278579627
2008	5.902256998397634
2009	11.878164506697683
2010	11.365506995031591
2011	6.9840525104641005
2012	7.657226654560096
2013	10.529991323553919
2014	14.314185595773768
2015	13.181932773481849
2016	11.057998652794767
2017	8.46161351245809
2018	9.248342489165784
2019	13.53500985123672
2020	5.952987040629996
2021	12.79291231494453
2022	9.259617666940896